Do American born Japanese children still grow faster than native Japanese?

Abstract

Growth patterns of Japanese schoolchildren in Hawaii, composed of 2,954 boys and 3,213 girls aged between 11 and 17, were compared with those comparable groups of Japanese schoolchildren in Japan based on the data published by the Japanese Ministry of Education. Growth characteristics studied were height, weight, and relative weight index, weight/(height). The Hawaii-Japanese boys were taller at early ages but the difference disappeared by age 16. Native Japanese girls were shorter than Hawaii-Japanese until age 13, but they overtook the latter by age 14, exceeding them in height after age 15. A similar pattern was found in weights of girls but the Hawaii-Japanese boys remained consistently heavier by 5.0 to 9.0 kg than native Japanese. The relative weight measure indicated that the Hawaii boys were more "obese" than native Japanese boys for the growth period studied; whereas the same tendency was maintained until age 15 in girls. These observations indicate a marked degree of convergence of the patterns of physical growth of the two populations, whose differences were unmistakably in favor of American born children in earlier studies. It is concluded that the convergence is due largely to the improved environmental conditions in Japan in recent years.